As is well known, thermal recording paper generates a colored image by thermally bringing a color former into contact with a color developer, which then develops a color. One of the advantages of the thermal recording paper is that it provides fairly easy maintenance of the recording apparatus, so it is now widely used as a recording medium for facsimiles, computer printers and measuring instrument printers. In the recording apparatus such as thermofacsimiles and thermoprinters, the thermal recording paper is printed with the recording head, cut with an autocutter, and discharged after passing through one or more pairs of guide rollers made of an electrically insulating material such as rubber or rigid plastics. To ensure reliable discharge, some types of apparatus arrange a discharge roller that is made of rubber or other electrically insulating materials after the auto-cutter, and which rotates at a peripheral speed slightly faster than the feed speed. In these types of apparatus, the back side of the recorded and cut paper is held in frictional contact with the discharge roller as it is being discharged, so in a low humidity atmosphere where the relative humidity is less than 40%, it often occurs that static charges built up on the recording paper cause "sticking" that prevents further discharge of the paper. Under even lower humidity conditions, "sticking" also takes place in other types of apparatus that do not use the discharge roller, because the friction of the paper against the surface of either guide roller before the auto-cutter causes a static charge buildup which prevents further feeding of the paper and may even damage the recording head.
A method has been proposed for eliminating sticking during the feeding or discharging of the thermal recording paper in a low humidity atmosphere by using a coating solution for the color generating layer that contains a large amount of sodium and other electroconductive ions. However, according to a study of the present inventors, this method of increasing the electroconductivity of the color generating layer by incorporating of a large quantity of conducting ions induces recording head wear. Furthermore, the method is hardly satisfactory when used in an apparatus that has a discharge roller, because the discharge roller is usually so arranged that its surface is in contact with the back side of the recording paper to protect the color generating layer.